HE GREATEST EPIPHANY in literature occurs when Oedipus sees that he himself is the fugitive murderer of the king. Two days ago the American cardinals were summoned to Rome by Pope John Paul II, and what they must report is an equivalent epiphany: The power structure of the Catholic Church itself - these self-same cardinals, this pope - is guilty of a heinous crime. The only hope of a staggered American Catholic Church is that our leaders, having at last faced the truth, will report in Rome what the broad experience of the American Catholic people has been and what the people now demand.

First, the cardinals must acknowledge that the hierarchy's impulse to protect itself has caused unspeakable harm to innocent people, especially children. The cardinals must be direct in saying to the pope that the church-sanctioned impulse to rally around besieged clerics, whether abusive priests or criticized bishops, has compounded the suffering of victims and enabled the escape of perpetrators.

Second, the cardinals must make it plain to the pope that only their accepting responsibility for inflicting this wound will enable it to heal.

Apparently Cardinal Law saw this last week when he offered his resignation to the Vatican, but it was rejected by a Vatican that was still rallying around besieged power. Instead of ritually offering to resign again, Law must simply inform the pope that his time as archbishop of Boston is over - a consequence of his betrayal of trust. Whether he returns to his residence on Lake Street or not, he has in effect been fired by the people of Boston. He should tell the pope that.

Third, the cardinals must make explicit for the pope the connection between their failure to protect the people and the closed, secretive clerical culture. Whatever causes predatory behavior by a few priests, the cause of the churchwide failure to stop them is clear - the lack of openness, due process, accountability, and full participation of the laity in church life. That the Globe had to force open abuse records by going to court is the shameful mark of this culture. To make the point clear, the cardinals should insist on open procedures now. Their discussions with the pope must not be yet another defensive clerical huddle behind closed doors.

Fourth, the cardinals should have a sense of history, understanding this as the end of a drama that began 132 years ago, the last time Roman Catholicism was in a state of such crisis. The threat then came from outside, as Italian nationalist revolutionaries attacked what were then the Papal States. The bishops responded by rallying around the besieged pope, and it was then, at the First Vatican Council in 1870, that they defined papal infallibility as doctrine, replacing the pope's temporal power over states with absolute spiritual power.

The impulse to rally blindly around besieged church authority at all levels begins here, and so does the so-called ''creeping infallibility'' that turns all authority figures in the church into petty tyrants. This absolutism, too, is a source of today's crisis.

Fifth, the American cardinals must bring to Rome a firm sense of their own Americanism. That the United States has been a center of priestly abuse is a humiliation - but an opportunity, too. The American impulse - democratic, egalitarian, preferring freedom to constraint - is the opposite of church absolutism, which is why, not long after the First Vatican Council, Rome condemned a democratic theology as the heresy of, yes, ''Americanism.''

But the true heresy is ''papalism.'' The cardinals must draw the connection between their failure and the lack of democratic structures in the church down to the parish level. The church must stop treating democracy as the enemy and such of its tenets as freedom of the press and the primacy of individual conscience as anathema.

Can any of this happen? Some have said it would require the death of the present absolutist pope for any of these changes to be contemplated. Perhaps not. John Paul II has shown that when faced with a harsh truth of history - he returned to his Polish hometown after World War II to find all its Jews gone, simply gone - he can be an agent of change. He has done more to heal the breach between Catholics and Jews than any previous pope. Now the needed healing must occur within the church.

When John Paul II looks into the eyes of the American cardinals next week and sees that the integrity of their authority is gone, simply gone - what will he do? The old man has one last opportunity for greatness - an opportunity presented by the awful truth of what the church has become.

This awful truth, like the awful truth Oedipus saw, can yet accomplish a catharsis. Or, to cite Jesus, this awful truth - even this - can make us free.